Can the 2021 Freightliner Sprinter make a U-turn?

No. Needs more than 40 ft.

40.7ft curb to curb

Street width, feet

Street 40 feet curb to curb.

2021 Freightliner Sprinter 1500 Cargo High Roof w/144" WB RWD. Top view, to scale.

2021 Freightliner Sprinter: turning circle by trim, 40 ft street
Trim	Circle, ft	Margin	One move
1500 Cargo High Roof w/144" WB RWD	40.7	-0.7 ft	No
1500 Cargo Standard Roof w/144" WB RWD	40.7	-0.7 ft	No
1500 Passenger High Roof w/144" WB RWD	40.7	-0.7 ft	No
1500 Passenger Standard Roof w/144" WB RWD	40.7	-0.7 ft	No
2500 Cargo High Roof Extended w/170" WB Extended RWD	47.2	-7.2 ft	No
2500 Cargo High Roof w/170" WB RWD	47.2	-7.2 ft	No
2500 Cargo Standard Roof w/144" WB RWD	40.7	-0.7 ft	No
2500 Crew High Roof w/170" WB RWD	47.2	-7.2 ft	No
2500 Crew Standard Roof w/144" WB RWD	40.7	-0.7 ft	No
2500 Passenger High Roof w/170" WB RWD	47.2	-7.2 ft	No
2500 Passenger Standard Roof w/144" WB RWD	40.7	-0.7 ft	No
3500 Cargo High Roof Extended w/170" WB Extended RWD	52.5	-12.5 ft	No
3500 Cargo High Roof w/170" WB RWD	52.5	-12.5 ft	No
3500 Cargo Standard Roof w/144" WB RWD	45.3	-5.3 ft	No
3500 Crew High Roof w/170" WB RWD	52.5	-12.5 ft	No
3500 Crew Standard Roof w/144" WB RWD	45.3	-5.3 ft	No
3500 XD Crew High Roof w/170" WB RWD	52.5	-12.5 ft	No
3500 XD Crew Standard Roof w/144" WB RWD	45.3	-5.3 ft	No
3500XD Cargo High Roof Extended w/170" WB Extended RWD	52.5	-12.5 ft	No
3500XD Cargo High Roof w/170" WB RWD	52.5	-12.5 ft	No
3500XD Cargo Standard Roof w/144" WB RWD	45.3	-5.3 ft	No
4500 Cargo High Roof Extended w/170" WB Extended RWD	52.5	-12.5 ft	No
4500 Cargo High Roof w/170" WB RWD	52.5	-12.5 ft	No
4500 Cargo Standard Roof w/144" WB RWD	45.3	-5.3 ft	No
4500 Crew High Roof w/170" WB RWD	52.5	-12.5 ft	No
4500 Crew Standard Roof w/144" WB RWD	45.3	-5.3 ft	No

What this cannot tell you

Curb-to-curb turning circle as listed.

Mirrors and overhang need more room.